I was also a bit confused as to why the title was "DarkMode Made Easy", especially since your example just showed adjusting CSS variables. I would assume anyone who's working with CSS variables, also knows about media queries, so it's far easier to just do it all in CSS.
Where I could see this being useful is that you have a callback that you can use, so when dark mode is enabled, you can make some other adjustments when needed.
Where I could see this being useful is that you have a callback that you can use, so when dark mode is enabled, you can make some other adjustments when needed.